1. Field of the Invention
The present invention relates to warning light systems intended primarily for installation on land and marine vehicles and particularly to a light bar assembly having an integrated modular design and a method of assembly therefor.
2. Description of the Related Art
Warning light assemblies in the form of light bars mounted on emergency vehicles are well known in the art. The modern trend is toward compact, low profile, self contained light bar assemblies. Compact and low profile light bar assemblies improve the aerodynamic efficiency and significantly reduce wind noise typically generated by a light bar.
U.S. Pat. No. 4,620,268 to Ferenc represents a significant advance in the design of such light bar assemblies. The Ferenc light bar is built around an I-beam structural member and includes lens elements that engage the front and rear edges of upper and lower horizontal structural elements of the I-beam so as to span the horizontal length of the light bar. Each end of the light bar assembly is provided with a molded plastic end cap which abuts the ends of the I-beam and lenses to define an enclosure.
While this design represents an important advance over the prior art and has enjoyed significant commercial success, the patented monolithic I-beam support member complicates the manufacture and service of the light bar assembly. The strengthening web connecting the upper and lower structural members of the I-beam support member holds the upper and lower portions at a fixed distance. Any light bar design requiring an alternative height must use a different I-beam support member. Additionally, since the top and bottom structural members of the I-beam are permanently attached to each other, any work on the interior of the light bar must be performed through openings at the ends and along the sides of the I-beam. Further, the space inside the I-beam support member is necessarily bifurcated by the support web. This bifurcated space is inherently less useful than a unitary space.
There is a modern trend toward self contained light bars where the light bar includes the power supplies and signal processing equipment necessary for operation of a light bar. Such self-contained assemblies are desirable because they require fewer interconnections with a host vehicle, simplifying installation and maintenance.
These and other deficiencies of the prior art are overcome by the present invention. A preferred embodiment of a light bar in accordance with the present invention comprises an elongated base and top panel supported above the elongated base by a plurality of ruggedly constructed electronics enclosures. The electronics enclosures serve multiple functions. First, each enclosure surrounds and supports the electronic components of the power supply. Second, each enclosure provides a robust mechanical connection between the base and top plate. Third, each enclosure includes means for transmitting heat generated within the power supply to an externally mounted heat sink plate. A thermal transfer interface is formed between the heat sink plate and the top plate.
An object of the present invention is to provide a light bar with improved ease of manufacture and maintenance.
Another object of the invention is to provide a new and improved light bar that can be assembled from interchangeable components into a variety of configurations.